How Do Two Agents Share One File?

They don’t, by design. A writing stage names the files it may write, and a file it changed that the workflow declared for another stage fails the stage. Attempts that must not touch each other run in separate worktrees, and only the winner lands. Obversa does not lock a file between two processes you started outside a workflow, and a file the workflow never declared is not part of the check.

In Obversa

The write stage declares its two files, and nothing else is its to change:

examples/teams/writer-reviewer-pair.ts (excerpt)

      stage('write', {
        agent: 'write',
        writes: ['src/add.mjs', 'test/add.test.mjs'],
        desc: 'Write the function and its test from the brief.',
        gate: 'The files named in the brief exist in the workspace.',
        retry: 1,
      }),

Declared writes are what the reviewer and the test stage read, and what the record shows the stage produced.

Workflow file

The declarations live in the workflow file, beside the roles and the stages. Should team rules live in AGENTS.md? says what belongs there.

Next steps

Workspace: a worktree per writer, captured and verified.
Three candidates, one winner: parallel attempts in their own worktrees.

Start

Concepts

Patterns

Examples

Evals and Gates

Recording Runs

Driving Runs

Surfaces and Hosts

Writing Workflow Shapes

Memory

Workspace

Compare

FAQ

API Reference

How Do Two Agents Share One File?

In Obversa

Workflow file

Next steps

​In Obversa

​Workflow file

​Next steps

In Obversa

Workflow file

Next steps